wildtuinman wrote:The last couple of days white butterflies are flying all over the place up here in Gauteng. Can anyone please tell me what they are and what their business is in flying around and spoiling my view thru my windscreen?

Glad you asked it, I was watching them yesterday and wondered the same thing ..

I think it has something to do with the rain ... lots of food and time to reproduce ....

But I would like to hear some experts opinion on them ...

Btw .. watch when you open your mouth ... you might just end up with 10 in your mouth ... Mind you ... the cats at our business complex are having a ball chasing them ..

They are actually around every year.
I must look through my notes I have written it down somewhere, but the reason is something like this...

These whites are actually migrating up into Africa (somewhere?), but something went wrong with the genetically imprinted route. Therefore they flutter around and never get going. Remember a butterfly has a short lifespan. Apparently the furhest some make is north of Hatrbeestpoort Dam...

I just can't remember where they were supposed to go, (Maybe I am one of them) but aparrently the same happens there. The whites there also cant remember the route back here...

The original idea was to migrate, breed somewhere in Africa and return breed here and migrate again...(why? does not make sense?) I'll look through the archives I had it somewhere..

beautiful butterflies indeed, they usually associated with shepherds tree's/ witgat as their larval host plant (F. capperaceae(?i think) def.Boscia spp.). which is very cosmopolitan.

as for the migration side of things i seem to recall this species always migrating north east, a coded signal harking back to when they made their way towards india. I cant find any literature to back that up but i read it somewhere and ill look for it too.

It seems like the "flies could be Boisduval's Tree nymph - according to Carruthers The Wildlife Of Southern Africa [/u], the description fits - they appear to hatch in one locality and disperse from there- does that fit?
My first post, after ages of viewing this site- my favourite! [/u]

The Brown Veined White (Belenois aurota) is one of the most common butterflies in Southern Africa. It is as exceedingly abundant insect, especially in open country, this butterfly has a low, fairly strong flight, which is frequently interrupted when it visits flowers and muddy puddles. This butterfly is on the wing throughout the year. Large migrations of this butterfly take place during the mid-rainy season in Southern Africa, up the east coast of Africa, towards Madagascar. As the butterfly migrates it lays its eggs on various host plants on the way.

This is basically correct!

The natural distribution of the Brown Veined White is throughout South Africa, but they are more at home in the western part of S.A. This migration is a yearly occurrence and is not at all strange! I can remember it from childhood days! Do not know why it is sudden big news in the papers? Probably because there is not enough "big news"!

They are more common in the arid west of S.A., including the Kalahari. In good rain years they produce excess population and can even have several generations in one season.

As soon as the population explodes stronger individuals are produced. This is in preparation for the migration, much as migratory birds prepare for a migration by stocking up on body fat. The migration occurs to prevent over exploitation of their food source. The movement is from the west to the east. It is however not a "real" migration, since there is no movement back the next season.

I do not know of scientific studies, but I presume that most of the individuals on the migration are killed, or fail to produce successfully in the east, since they are not as ideally adapted for the habitat in this area, as in the west.

Just returned from the Free State and they were everywhere. I do recall seeing this amount before... but I am not having an aha moment right now.
I do think this year is more prolific.
Wonder if that might be across species, such as locusts.

The bird doesn't sing because it has answers, it sings because it has a song.

Last night at around 6pm we were sitting in the garden when suddenly large numbers of the white butterflies appeared. These are the ones that fly east into Mozambique every year after laying their eggs. Isn't it a bit early for this mass 'migration' of white butterflies?

"In the end we conserve only that which we love, we love only that which we understand, we understand only that which we are taught" (Baba Dioum, Senegalese Ecologist)

Those white butterflies are brown-veined whites (Belenois aurota), and they don't really migrate. Migrating species return to the area where they migrate from, like the wildebeest in the Serengeti / Masai Mara. Brown-veined whites often undergo a huge population explosion in the Kalahari area, and when they have stripped their foodplants (Sheppard's trees / Boscia albitrunca) completely, they start moving off. They basically fly until they drop dead or reach the sea, and plaster every suitable plant in their way when they do this. So there isn't really a fixed time for the "migration" that we know so well. I hope this helps.

"If you can only visit two continents in your lifetime, visit Africa.... TWICE" - R.Elliot